Pole, Cover Plate Assembly and Battery Cell

The present application claims priority of Chinese Patent Application No. 202422195845.2, filed on Sep. 6, 2024. The entire disclosure of the prior application is hereby incorporated by reference.

The present application relates to the field of battery technology, including to a pole, a cover plate assembly and a battery cell.

A pole is an important component for connecting the inside and outside of a battery cell. One end of the pole is connected with an external circuit of the battery cell, and the other end is connected with an internal electrode assembly of a power battery. In order to reduce costs and weight, the external circuit of the battery cell adopts aluminum material for current transmission. However, inside the battery cell, a negative-electrode current collector and a current collector of a negative electrode sheet are made of the same material, which is copper material. Therefore, in order to improve conductivity of the pole and control weight and cost of the battery cell, a composite pole is adopted to connect the negative-electrode current collector with the external circuit. The copper composite pole includes an aluminum part and a copper part connected to one end of the aluminum part. The copper part is located inside the battery cell and is connected with the negative-electrode current collector. The aluminum part penetrates through a cover plate of the battery cell, and one end of the aluminum part away from the copper part is connected with the external circuit.

Due to different melting points and different material fluidity of materials of the copper part and the aluminum part, combination reliability between them is poor, resulting in poor reliability of the pole. Based on this, how to improve reliability of the composite pole is a problem to be solved by the present disclosure.

The present disclosure provides a pole, a cover plate assembly and a battery cell, which can improve reliability of a composite pole.

In an aspect of the present disclosure provide a pole, including a first metal part and a second metal part; where the first metal part has an outer peripheral surface, and the outer peripheral surface is provided with an embedded groove; and, the second metal part is provided with a connecting groove, where one end of the first metal part is embedded into the connecting groove, an embedding block is provided protruding from a groove wall of the connecting groove toward the first metal part, and the embedding block is embedded into the embedded groove; wherein material of the first metal part is different from material of the second metal part, a thickness of the groove wall of the connecting groove is D, and along a radial direction of the pole, a depth dimension of the embedding block embedded into the embedded groove is L1, satisfying: 0<L1≤0.5D.

In an aspect, in an axial direction of the pole, the embedding block has a height dimension H1, satisfying: D≤H1≤3D.

In an aspect, the embedding block comprises a first embedding portion and a second embedding portion, wherein the first embedding portion is arranged to extend radially inward from a side of the groove wall of the connecting groove close to an opening of the connecting groove, and the second embedding portion is arranged to extend axially outward from a side of the first embedding portion away from a groove bottom of the connecting groove.

In an aspect, a side wall of the second embedding portion away from an axis of the pole is coplanar with the outer peripheral surface.

In an aspect, in the axial direction of the pole, the second embedding portion has a height dimension H2 satisfying: 0.5D≤H2≤2D.

In an aspect, the embedded groove is arranged to extend along a circumferential line of the outer peripheral surface, and the embedding block is arranged to extend along the circumferential line of the outer peripheral surface.

In an aspect, both the embedded groove and the embedding block extend along the circumferential line of the outer peripheral surface to form an annular shape.

In an aspect, a plurality of embedded grooves is provided, wherein the plurality of embedded grooves is disposed at intervals along the circumferential line of the outer peripheral surface; and, a plurality of embedding blocks is provided, wherein the plurality of embedding blocks is in one-to-one correspondence with the plurality of embedded grooves.

In an aspect, a wall thickness of a groove bottom of the connecting groove is consistent with a wall thickness of the groove wall of the connecting groove.

In an aspect, the first metal part is of aluminum material, and the second metal part is of copper material.

In an aspect of the present disclosure provide a cover plate assembly including a cover plate, a pole, a terminal, an upper plastic part, a lower plastic part, a current collector, a sealing ring and the aforementioned pole, where the pole penetrates through the cover plate; the terminal is located on one side of the cover plate and connected with the pole; the upper plastic part is disposed between the terminal and the cover plate; the lower plastic part is disposed on another side of the cover plate; the current collector is connected with one end of the pole away from the terminal; and, the sealing ring is disposed between the pole and a mounting hole; wherein the material of the first metal part is consistent with material of the current collector, the first metal part is connected with the current collector, and the terminal is connected with the second metal part; or, the material of the second metal part is consistent with the material of the current collector, the second metal part is connected with the current collector, and the terminal is connected with the first metal part.

In an aspect of the present disclosure provide a battery cell including a casing, an electrode assembly and the aforementioned cover plate assembly; where the casing has a containing cavity; the electrode assembly is disposed in the containing cavity; and, the cover plate is connected with the casing and closes an opening of the containing cavity, and the current collector is further connected with the electrode assembly.

Beneficial effects of the examples of the present disclosure are as follows.

In the examples of the present disclosure, by embedding the second metal part into the embedded groove of the first metal part through the embedding block and limiting the embedding depth, on one hand, the first metal part and the second metal part can be locked with each other in the axial direction of the pole, so as to effectively prevent the first metal part and the second metal part from being disconnected; on the other hand, the cross-sectional dimension of the first metal part at the embedded groove can be guaranteed to ensure strength of the first metal part, thereby improving performances such as tensile resistance and shock resistance of the pole. In this way, reliability of the pole can be improved.

11 112 1121 1122 113 1131 1132 1133 1134 1135 1136 1137 : pole;: first metal part;: embedded groove;: outer peripheral surface;: second metal part;: connecting groove;: embedding block;: first surface;: first embedding portion;: second embedding portion;: groove bottom;: groove wall; 118 : step; 12 : terminal; 2 21 22 23 24 : cover plate assembly;: cover plate;: upper plastic part;: lower plastic part;: current collector.

The technical solutions in the examples of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the examples of the present disclosure. Obviously, the described examples are merely some examples rather than all the examples of the present disclosure. Based on the examples in the present disclosure, other examples obtained by those skilled in the art without making creative labor shall fall within the protection scope of the present disclosure.

In addition, it should be understood that the specific implementations described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure. In the present disclosure, the terms “first” and “second” are only used for descriptive purposes, and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, a feature defined with “first” or “second” may explicitly or implicitly include one or more of the features. In the description of the present disclosure, “a plurality of” means two or more unless otherwise explicitly and specifically defined.

In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms “install”, “connect” and “connection” shall be understood in a broad sense. For example, they may be fixed connection, detachable connection, or integral connection; may be mechanical connection, and electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific situations.

The term “include”, “comprise” or any other variants thereof is intended to cover non-exclusive inclusion, so that a product including a series of elements not only includes those elements, but also includes other elements not explicitly listed.

In the description of the examples of the present disclosure, words such as “example” or “for example” are used for illustration, explanation or description. Any embodiment or design scheme described as “example” or “for example” in the present disclosure shall not be interpreted as being more preferred than or having more advantages over another. The words such as “example” or “for example” are intended to present relative concepts in a clear manner.

To facilitate the understanding of the solutions of the present disclosure, the spline curves and arrows used for reference signs in the drawings are explained here: components indicated by spline curves without arrows are solid components, that is, components with a solid structure; components indicated by spline curves with arrows are virtual components, that is, components without a solid structure.

1 FIG. 11 11 112 113 112 1122 1122 1121 113 1131 112 1131 1132 1131 112 1132 1121 112 113 1131 11 1132 1121 Please refer tothe present disclosure provides a pole. The poleincludes a first metal partand a second metal part. The first metal parthas an outer peripheral surface. The outer peripheral surfaceis provided with an embedded groove. The second metal partis provided with a connecting groove. One end of the first metal partis embedded into the connecting groove. An embedding blockis provided protruding from the groove wall of the connecting groovetoward the first metal part. The embedding blockis embedded into the embedded groove. The material of the first metal partis different from the material of the second metal part. The thickness of the groove wall of the connecting grooveis D. In the radial direction of the pole, the depth dimension of the embedding blockembedded into the embedded grooveis L1, satisfying: 0<L1≤0.5D.

1132 1121 It can be understood that the depth dimension L1 of the embedding blockembedded into the embedded grooveincludes but is not limited to 0.1D, 0.15D, 0.2D, 0.23D, 0.28D, 0.3D, 0.36D, 0.39D, 0.4D, 0.42D, 0.45D, 0.46D, and 0.5D.

11 113 1132 1121 Exemplarily, taking a certain square poleas an example, the wall thickness D of the second metal partadopted thereby is 0.5 mm. Correspondingly, the depth dimension L1 of the embedding blockembedded into the embedded grooveis 0<L1≤0.25 mm.

12 24 12 In addition, the first metal part is electrically connected with the current collector, and the first metal part is of copper material; correspondingly, the second metal part is of aluminum material and is connected with the terminal. Alternatively, the second metal part is electrically connected with the current collector, and the second metal part is of copper material; and, the first metal part may be of aluminum material and is connected with the terminal.

112 113 112 1132 1121 1132 1121 It can be understood that the first metal partmay be formed by casting first, and then the second metal partmay be cast on the first metal part, so that the embedding blockis matched with the embedded groove; alternatively, an upsetting method may be adopted to make the embedding blockmatched with the embedded groove.

1121 1132 112 113 11 112 113 112 1121 112 11 11 In an example, by embedding the second metal part into the embedded grooveof the first metal part through the embedding blockand limiting the embedding depth, on one hand, the first metal partand the second metal partcan be locked with each other in the axial direction of the pole, so as to effectively prevent the first metal partand the second metal partfrom being disconnected; on the other hand, the cross-sectional dimension of the first metal partat the embedded groovecan be guaranteed to ensure the strength of the first metal part, thereby improving performances such as tensile resistance and shock resistance of the pole. In this way, the reliability of the polecan be improved.

11 11 11 11 1 FIG. 2 FIG. 2 FIG. In addition to the structure of the poleshown in, the polein the present example may also be shown in other structures. For example, the structure of the poleshown in, whereis a schematic structural diagram of a second kind of a poleprovided by examples of the present disclosure.

1132 1121 1121 11 Moreover, limiting the maximum value of the depth dimension L1 of the embedding blockembedded into the embedded groovecan improve the uniformity of the flow of the second metal part in the embedded groovewhen the poleis formed by upsetting, and can avoid the second metal part from being torn.

1 FIG. 11 1132 Please refer to. In an example, in the axial direction of the pole, the embedding blockhas a height dimension H1 satisfying: D≤H1≤3D.

1132 It can be understood that the height dimension H1 of the embedding blockincludes but is not limited to D, 1.2D, 1.5D, 1.6D, 1.8D, 1.9D, 2D, 2.2D, 2.3D, 2.5D, 2.6D, 2.7D, 2.8D, 2.9D, and 3D.

1132 112 113 112 113 11 In the present example, by limiting the height dimension H1 of the embedding block, on one hand, it can avoid insufficient strength of the embedding portion between the first metal partand the second metal partcaused by the height dimension being too small, thereby effectively ensuring the combination reliability between the first metal partand the second metal part; on the other hand, it can avoid high material cost caused by the height dimension being too large, so as to control the material cost of the poleand help improve the economy of the battery cell.

3 FIG. 4 FIG. 3 FIG. 4 FIG. 3 FIG. 11 1132 1134 1135 1134 1137 1131 1131 1135 1134 1136 1131 118 113 1135 11 118 11 113 1132 112 113 Please refer toand.is a schematic structural diagram of a third kind of a poleprovided by examples of the present disclosure, andis an enlarged view of portion B in. In an example, the embedding blockincludes a first embedding portionand a second embedding portion. The first embedding portionis arranged to extend radially inward from a side of the groove wallof the connecting grooveclose to the opening of the connecting groove, and the second embedding portionis arranged to extend axially outward from a side of the first embedding portionaway from the groove bottomof the connecting groove. In this way, a stepis formed between the second metal partand the second embedding portion. Therefore, when the poleis connected with other components, other components can be positioned based on the step. In this way, not only the operability of connection between the poleand other components can be improved, but also the part of the second metal partlocated at the embedding blockcan be limited by other components, so as to improve the combination reliability between the first metal partand the second metal part.

112 113 12 112 113 118 2 12 11 11 11 12 113 112 118 Moreover, when the first metal partis of copper material and the second metal partis of aluminum material, the terminalis sleeved on one end of the first metal partaway from the second metal partand is in stopping fit with the step. Then, after all main components of the cover plate assemblyare assembled and before the terminalis welded with the pole, upsetting is performed on the pole, so that the polecan expand radially and a combination surface of aluminum (terminal)-copper (second metal part)-aluminum (first metal part) is formed at the step. Due to the different fluidity of different metals, the combination surface of aluminum-copper-aluminum is uneven, so that the combination is more reliable.

118 1133 11 11 1133 11 1133 The stepincludes a first surfaceperpendicular to the axis of the poleand a peripheral wall disposed around the axis of the pole. The first surfaceextends along the circumferential line of the poleto form an annular shape, and the inner diameter side of the first surfaceis connected with one end of the peripheral wall.

3 FIG. 1135 11 1122 11 Please refer to. In an example, the side wall of the second embedding portionaway from the axis of the poleis coplanar with the outer peripheral surface. In this way, the surface structure of the polecan be regular, which is conducive to simplifying the structure of the components matched with it.

112 12 12 112 113 118 1132 11 1122 12 1122 12 For example, when the first metal partis matched with the terminal, the terminalis sleeved on one end of the first metal partaway from the second metal partand is in stopping fit with the step. Since the side wall of the embedding blockaway from the axis of the poleis coplanar with the outer peripheral surface, the hole on the terminalmatched with the side wall and the outer peripheral surfacecan be an equal-diameter hole, so as to simplify the production process of the terminal.

3 FIG. 11 1135 Please refer to. In an example, in the axial direction of the pole, the second embedding portionhas a height dimension H2 satisfying: 0.5D≤H2≤2D.

1132 1131 It can be understood that the height dimension H2 of the part of the embedding blocklocated outside the connecting grooveincludes but is not limited to 0.5D, 0.6D, 0.8D, 1D, 1.1D, 1.2D, 1.5D, 1.6D, 1.8D, and 2D.

113 118 118 1132 1132 1132 1121 112 112 In the present example, through the above limitation, on one hand, the second metal partcan be guaranteed to have a sufficient height dimension H2 on the formed step, which is conducive to increasing the matching surface between the component matched with the stepand the embedding block, thereby improving the limiting effect of the component on the embedding block, so that the embedding blockis stably matched with the embedded groove; on the other hand, it can avoid excessive height dimension H2 from covering more peripheral side wall of the first metal part, thereby ensuring that the peripheral side wall of the first metal parthas a sufficient area for connecting with other components.

1121 1122 1132 1121 1121 1132 112 113 In an example, the embedded grooveis arranged to extend along the circumferential line of the outer peripheral surface, and the shape and size of the embedding blockare consistent with the shape and size of the embedded groove. In this way, the matching area between the embedded grooveand the embedding blockcan be increased, so as to improve the combination reliability between the first metal partand the second metal part.

1132 1121 1132 1121 112 113 It can be understood that the shape and size of the embedding blockare consistent with the shape and size of the embedded groove, means that the embedding blockand the embedded groovemay have dimensional errors within a certain range, and such dimensional errors do not affect the connection between the first metal partand the second metal part.

1132 1131 1121 1132 1131 In addition, it can be understood that when upsetting forming is adopted, the side of the embedding blockaway from the groove bottom of the connecting groovemay be in contact with the groove wall of the embedded groove, or there may be a gap. Moreover, the side of the embedding blockaway from the groove bottom of the connecting groovemay be a coplanar structure, or an uneven structure formed by upsetting, or other structures.

5 FIG. 5 FIG. 3 FIG. 1121 1122 1121 1132 112 113 Please refer to,is a cross-sectional view along A-A inprovided by examples of the present disclosure. In an example, the embedded grooveextends along the circumferential line of the outer peripheral surfaceto form an annular shape. In this way, the matching area between the embedded grooveand the embedding blockcan be increased, so as to improve the combination reliability between the first metal partand the second metal part.

112 113 Moreover, such an arrangement can also increase the embedding strength between the first metal partand the second metal partto avoid relative rotation between them.

3 FIG. 6 FIG. 6 FIG. 3 FIG. In another example, the cross-sectional view along A-A inmay be rectangular, as shown in,is another cross-sectional view along A-A inprovided by examples of the present disclosure.

7 FIG. 7 FIG. 3 FIG. 1121 1121 1122 1132 1132 1121 1121 1132 112 113 Please refer to,is yet another cross-sectional view along A-A inprovided by examples of the present disclosure. In an example, a plurality of embedded groovesare provided. The plurality of embedded groovesare disposed at intervals along the circumferential line of the outer peripheral surface. A plurality of embedding blocksare provided, and the plurality of embedding blocksare in one-to-one correspondence with the plurality of embedded grooves. In this way, the matching area between the embedded groovesand the embedding blockscan be increased, so as to improve the combination reliability between the first metal partand the second metal part.

1121 1122 The plurality of embedded groovesare evenly distributed at intervals along the circumferential line of the outer peripheral surface.

3 FIG. 1131 1131 Please refer to. In an example, the wall thickness of the groove bottom of the connecting grooveis consistent with the wall thickness of the groove wall of the connecting groove.

1131 1131 11 It can be understood that both the wall thickness of the groove bottom of the connecting grooveand the wall thickness of the groove wall of the connecting grooveare D. Of course, after the poleis formed by upsetting, the wall thickness of the groove bottom and the wall thickness of the groove wall may have a difference within a certain range, and the wall thickness of the groove bottom and the wall thickness of the groove wall within this difference can be regarded as consistent.

113 In the present example, through the above arrangement, the structure of the second metal partis simple and easy to form.

112 113 11 11 11 In an example, the first metal partis of aluminum material, and the second metal partis of copper material. In this way, a structure in which the aluminum part is covered by the copper part is formed. On one hand, this can make the polehave a larger copper surface, which is conducive to ensuring the reliability of the connection between the poleand the current collector; on the other hand, the aluminum material can be protected based on the higher strength and durability of the copper material compared with the aluminum material, so as to reduce the risk of damage to the pole.

8 FIG. 2 2 21 11 12 22 23 24 11 11 21 12 21 11 22 12 21 23 21 24 11 12 11 112 24 112 24 12 113 113 24 113 24 12 112 Please refer to. Correspondingly, examples of the present disclosure further provide a cover plate assembly. The cover plate assemblyincludes a cover plate, a pole, a terminal, an upper plastic part, a lower plastic part, a current collector, a sealing ring, and the aforementioned pole. The polepenetrates through the cover plate. The terminalis located on one side of the cover plateand connected with the pole. The upper plastic partis disposed between the terminaland the cover plate. The lower plastic partis disposed on another side of the cover plate. The current collectoris connected with one end of the poleaway from the terminal. The sealing ring is disposed between the poleand a mounting hole. The material of the first metal partis consistent with the material of the current collector, the first metal partis connected with the current collector, and the terminalis connected with the second metal part; or, the material of the second metal partis consistent with the material of the current collector, the second metal partis connected with the current collector, and the terminalis connected with the first metal part.

112 112 24 12 113 113 113 24 12 112 It can be understood that when the first metal partis of copper material, the first metal partis connected with one end of the current collector, and the terminalis connected with the second metal part; and, when the second metal partis of copper material, the second metal partis connected with one end of the current collector, and the terminalis connected with the first metal part.

11 112 113 11 112 113 112 113 11 112 113 2 In the present example, by adopting the poleprovided by some examples of the present disclosure, on one hand, the first metal partand the second metal partcan be locked with each other in the axial direction of the pole, so as to effectively prevent the first metal partand the second metal partfrom being disconnected; on the other hand, the strength of the embedding structure between the first metal partand the second metal partcan be guaranteed, thereby improving performances such as tensile resistance and shock resistance of the pole. In this way, the combination reliability between the first metal partand the second metal partcan be improved, so as to improve the reliability of the cover plate assembly.

2 21 24 Correspondingly, examples of the present disclosure further provide a battery cell. The battery cell includes a casing, an electrode assembly, and the aforementioned cover plate assembly. The casing has a containing cavity. The electrode assembly is disposed in the containing cavity. The cover plateis connected with the casing and closes an opening of the containing cavity. The current collectoris further connected with the electrode assembly.

2 112 113 11 112 113 112 113 11 112 113 In the present example, by adopting the cover plate assemblyprovided by some examples of the present disclosure, on one hand, the first metal partand the second metal partcan be locked with each other in the axial direction of the pole, so as to effectively prevent the first metal partand the second metal partfrom being disconnected; on the other hand, the strength of the embedding structure between the first metal partand the second metal partcan be guaranteed, thereby improving performances such as tensile resistance and shock resistance of the pole. In this way, the combination reliability between the first metal partand the second metal partcan be improved, so as to improve the reliability of the battery cell.

The technical solutions and technical effects of the present disclosure will be described in detail below through specific examples. The following examples are only part of the examples of the present disclosure and do not specifically limit the present disclosure.

1132 1121 11 1132 1121 1121 The present example aims to investigate the influence of the depth dimension L1 of the embedding blockembedded into the embedded grooveon the tensile performance of the pole. It can be understood that the depth dimension of the embedding blockembedded into the embedded grooveis consistent with the depth dimension of the embedded groove.

The test contents are described as follows:

(1) The simulation software used for the test is LSDYNA. 112 113 (2) The first metal partis of aluminum material with an outer diameter of 20 mm; and, the second metal partis of copper material with a thickness D of 0.8 mm. 1132 1121 (3) The height dimension H1 of the embedding blockembedded into the embedded grooveis 0.8 mm.

11 11 Poleswith L1 being 0.4D=0.32 mm, 0.5D=0.4 mm, D=0.8 mm and 2D=1.6 mm respectively are selected for tensile tests, and the tensile force values at which the polesare damaged are as follows:

TABLE 1 Tensile test of pole 011 D L1 F/N 0.8 mm 0.4D = 0.32 37215N 0.5D = 0.4 mm 36473N 0.6D = 0.48 mm 36110N D = 0.8 mm 32701N 2D = 1.6 mm 26746N

11 112 The damage of the polemainly refers to the damage of the first metal part.

1132 1121 11 11 11 11 It can be known from Table 1 that as the depth dimension L1 of the embedding blockembedded into the embedded grooveincreases, the tensile force value at which the poleis damaged gradually decreases, that is, the tensile performance of the polegradually decreases. When the tensile performance of the poleis 36110N, the strength requirement of the poleis not met.

112 113 11 1132 1121 Therefore, while meeting the embedding requirements between the first metal partand the second metal part, in order to ensure the tensile strength of the pole, the depth dimension L1 of the embedding blockembedded into the embedded grooveshould not be greater than 0.5D.

The examples of the present disclosure are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation manners of the present disclosure. The description of the above examples is only used to help understand the method and core idea of the present disclosure; meanwhile, for those skilled in the art, according to the idea of the present disclosure, there will be changes in the specific implementation manners and disclosure scopes. In conclusion, the content of this specification should not be understood as a limitation to the present disclosure.